Prevalence and zoonotic implications of bovine tuberculosis in Northwest Ethiopia

Abstract

A cross sectional study on bovine tuberculosis (BTB) was conducted in Northwest Ethiopia, Gondar 
and Dembia districts, from October 2007 to March 2008 to determine the prevalence and assess its 
zonnotic impact. Both questionnaire survey and comparative intradermal tuberculin test (CIDT) were 
used for this study.  For the comparative intradermal tuberculin test (CIDT) test 311 cross breed cattle 
were considered whereas a total of 77 households were interviewed for the presence of tuberculosis 
cases within their family and habit of raw milk consumption. The result of CIDT indicates that the 
overall prevalence of bovine tuberculosis was 7.1%. In the outdoor and indoor management system 
individual animal prevalence of BTB was 4.5% (4/88) and 8.1% (18/223) respectively. The herd 
prevalence of bovine tuberculosis in outdoor and indoor production systems were 12.9% (4/31) and 
26.1% (12/46), respectively. There was no significant difference between the two production systems (x2 
= 1.2, df = 1, p > 0.05). The prevalence of BTB in age group 4 up to 7 year (12.1%), was significantly (x2 = 
9.76, df = 2, P<0.05) higher than that of age group up to 3  year (2.8%), and age groups greater than 7 
year (3.45%). Similarly, the prevalence of BTB in fat, medium, lean and emaciated body condition was 
40, 5.46, 2.27 and 0% respectively, showing highly significant difference (x2 = 36.1, df =3, p < 0.01). There 
were no significant association between reactors and respiratory symptoms (P > 0.05). There was, 
however, no statististically significant difference among tuberculosis cases that had the habit of raw 
milk consumption and those who do not have the habit (P > 0.05). In conclusion, tuberculosis was 
found to occur both in Gondar and Dembia districts. The knowledge cattle raising family about BTB was 
poor and their milk consumption habit could favor the transmission of the diseases from animals to 
human. This study discloses the potential risk factors for BTB in Gondar and Dembia districts.